Teacher professional knowledge is a combination of diverse types of knowledge.

Three main types of knowledge are identified through the Schulman model: SMK, PK and PCK. Most of the literature addresses the PCK and there is a lack of studies exploring either the nature of PK or the linkage between PK and PCK.

On one hand, we know that PCK improves depending on teacher experience: lesson after lesson, year after year, teachers refine their PCK when they encounter students' difficulties towards a specific notion. This is an unsatisfactory way of improving teachers' practices for the adaptation process is too long and insecure. This is a reason why the 'lesson studies' framework leads to minimize the weakness of this process.

This process raises a first question about the nature of teacher professional knowledge which underpins the first stage of such an evolution. The question is: What kind of knowledge is actualized during the beginning stages of a new lesson when the set of PCK is limited? We could hypothesize that teachers rely on PK as a kind of generic knowledge that allow them to cope with students difficulties. Accordingly, this is important to explore such PK.

This raises a second question addressing the way of overpassing these first stages. The question is: What kind of resources might help teachers to elaborate efficient and coherent PCK during these stages? We could hypothesize that teachers could benefit from resources helping to foresee students’ misconceptions and to improve specific SMK toward a notion.

On a second hand, subject teachers are not isolated within a school and they have to share constructs and methods with their colleagues from other subjects. Thus, they need PK as generic knowledge helping them to cross the boundaries amongst subjects. The questions are: How can we identify the set of PK shared by teachers? What kind of teacher work organization could help teachers from a same school to extent the PK that they share?

The symposium aims to explore the nature of PK and the linkage between PK and PCK. In order to limit the field of the investigation, the symposium will tackle only science teaching (maths, sciences, technology).

These inputs entail some change in the way teacher education and CPD program need to be designed and carrying out. The major problem might be twofold: a better understanding of the linkage between firstly CK and PCK, and secondly PCK and PK. The discussion will focus on these questions and implications for teacher education (initial and in-service). Some perspectives will be outlined regarding the possible interactions with policy makers and towards further research.